Fuel cap on my R3 hissing

[Tal]

Just completed a 1000km ride...Its summer here with temperatures up to 29c some days. Ive noticed when i turn the bike off there is pressure escaping from the fuel cap. Today in fact after refueling, there was petrol leaking out from the cap, i must have over filled it i guess. When i stopped and released the cap petrol blew out and ran down the tank!..all i had was my neck warmer to clean the fuel up.
What is the problem here...ideas?

 

[2023R3GT]

Im not sure if it supposed to do that - have overfilled mine, no leaks. It does release pressure when opening but its should not blow the fuel out too.
seem a video at high altitude - when opened it looks like shaked soda can, must be high pressure differentials…

again, under normal conditions this should not happen…

 

[Mongler07]

It's not uncommon for the pressure /drain hose to get pinched during an assembly or on some bikes like my ninja for the seat to squish it. Never had it happen on a rocket for me but on other bikes and ATVs it has. Find the drain vent line and make sure it's not clogged or pinched.

 

[sepfj]

Just completed a 1000km ride...Its summer here with temperatures up to 29c some days. Ive noticed when i turn the bike off there is pressure escaping from the fuel cap. Today in fact after refueling, there was petrol leaking out from the cap, i must have over filled it i guess. When i stopped and released the cap petrol blew out and ran down the tank!..all i had was my neck warmer to clean the fuel up.
What is the problem here...ideas?

I've had fuel leak out from the cap twice and both times I had placed the fuel cap upside down on the top of the pump while I filled the tank. In my case it didn't gush out when I removed the cap. It just seemed to be sloshing out the vent while riding. The only way I was able to stop the leaking was to remove the fuel cap and tap the bottom of the cap firmly on a hard surface. It seems that the vent inside the cap gets stuck open when I place the cap upside down and doesn't seat properly when put back in the tank. I now shake the bike side to side after filling to make sure no gas is leaking around the cap before pulling away. I haven't had a problem though since I started placing the cap right side up while I'm filling the tank and I tend to fill it a little higher than I should most of the time. (I do leave a little more air space if the temperature outside is extremely hot or the bike is hot and is going to be sitting for a while right after filling)

 

[Tal]

I've had fuel leak out from the cap twice and both times I had placed the fuel cap upside down on the top of the pump while I filled the tank. In my case it didn't gush out when I removed the cap. It just seemed to be sloshing out the vent while riding. The only way I was able to stop the leaking was to remove the fuel cap and tap the bottom of the cap firmly on a hard surface. It seems that the vent inside the cap gets stuck open when I place the cap upside down and doesn't seat properly when put back in the tank. I now shake the bike side to side after filling to make sure no gas is leaking around the cap before pulling away. I haven't had a problem though since I started placing the cap right side up while I'm filling the tank and I tend to fill it a little higher than I should most of the time. (I do leave a little more air space if the temperature outside is extremely hot or the bike is hot and is going to be sitting for a while right after filling)

That might help...i too place the cap upside down when im refueling...i'll try giving it a tap as you do and not put it upside down...thanx...

 

[Tal]

It's not uncommon for the pressure /drain hose to get pinched during an assembly or on some bikes like my ninja for the seat to squish it. Never had it happen on a rocket for me but on other bikes and ATVs it has. Find the drain vent line and make sure it's not clogged or pinched.

Yes...i suspect that too..its a right royal pain in the arse lifting the tank so i hope its not that..

 

[sunny]

normal to hiss here and there but should not hiss continuously

 

[Tal]

normal to hiss here and there but should not hiss continuously

I havnt encountered this hiss b4...?...

 

[TURBO200R4]

Yes...i suspect that too..its a right royal pain in the arse lifting the tank so i hope its not that..

Just an observation while reading this thread
Ok not pulling the tank
just relieving the pressure
That might be kinking the vent hose.
Be careful not to dump a bunch of ga

 

[Tal]

So i went out to the bike and sat there looking at it and decided i would get the key and lock the cap...i never do this..ever!.
I found if i put the cap on, ..turn it till it clicks a couple of times then get hold of it by those two lugs at the top, i cant get any sideways movement..its fairly tight. If i lock the cap once ive put it on..then get hold of those two lugs then there is some sideways movement...go figure?...maybe this will let the tank vent?..i dunno but ill try it.
I also tapped the cap on my work bench vice...maybe the foofoo valve has come free...we will see i guess...